The invention relates to a one-way package for fluids. For supplying coffee machines with coffee in extract form it is already known, in place of a refillable container which forms part of the automatic machine, to use a one-way package of the above-mentioned kind. Machine maintenance is considerably simplified in that the parts requiring cleaning are formed by the one-way package, the work of refilling being also accomplished by inserting the one-way package.
When the full package is inserted in the automatic machine the parts of the extraction duct located before and after the metering chamber are taken between squeezing mechanisms, while a pipe for heated water, controlled by a valve, is connected to a connecting piece of the package which discharges into the metering chamber. In order to prevent the undesired emptying of the package during transport, when being stored and while being inserted into the machine, the outlet opening and the water connecting piece are shut off by closures which are removable after insertion.
During the extraction of fluid from the package storage space, the squeezing mechanism located after the metering chamber is closed, while the squeezing mechanism located ahead of the metering chamber is opened. The metering chamber is filled under the static pressure of the fluid in the storage space. For the delivery of the metered quantity the squeezing mechanism located ahead of the metering chamber is closed, while the squeezing mechanism located after the metering chamber and also the valve of the water pipe are opened.
On the one hand, the known package has the disadvantage that when the one-way package is inserted into the automatic machine the water connecting piece has to be opened by removing the closure. Extract fluid cannot then be prevented from flowing out of the connecting piece and dirtying the machine.
On the other hand, there exists the disadvantage that as emptying of the storage space proceeds, the time required to fill the metering space which, owing to the high viscosity of the extract fluid is in any case relatively long, increases. A time control provided in the automatic machine must therefore be set to the longest possible metering space filling time. Furthermore, a new metering operation cannot be initiated until the assigned quantity of water has also flowed through the metering space. The efficiency of a machine served by packages of this type is correspondingly limited.